Tritium is a naturally occurring radionuclide,
due to interactions of cosmic-rays with the upper layers of
the atmosphere; but its presence in the environment is
mainly due to residual fallout from nuclear weapons
atmosphere tests, carried out from 1952 till 1980. Tritium
reaches the Earth’s surface mainly in the form of precipitation,
becoming part of the hydrological cycle, then the
interest of tritium content analysis in drinking water is both
for dosimetry and health-risk and for using tritium as a
natural tracer in the groundwater circulation system. This
paper presents results from a survey carried out in the Mt.
Etna area (east and west flanks) and in the southern side of
Nebrodi in Sicily (Italy), in order to determine tritium
activity concentrations in water samples by using liquid
scintillation counter. The investigated areas show quite low
tritium concentrations, much below the Italian limit of
100 Bq L-1 for drinking water and even comparable with
the minimum detectable activity value. The effective dose
due to tritium for public drinking water consumption was
also evaluated.